In the harvesting of a forage crop material, the material after being cut, is generally permitted to dry at least to a limited extent and then formed into windrows. The windrows are then made up into rolled tight bales each of which is usually secured by binder twine extended spirally around the bale. One advantage of rolled bales is that they may be stored in the field since their cylindrical form provides a natural means to shed water when rained upon. However, the outermost portions of such rolled bales may deteriorate if left exposed over a period of time.
To reduce such deterioration, the bales may be protected by a covering material such as sheet plastic, as disclosed in U.S. Pat. No. 4,173,112. In the German published application No. 2,705,101, filed Nov. 23, 1978, a rolled bale is wrapped in plastic material of a ribbon form which is wound spirally around the bale with the edges thereof in an overlapping relation. The wrapping of packages or stacked items by a plastic sheet material is shown in U.S. Pat. Nos. 3,514,920; 3,986,611; and 4,299,076. In U.S. Pat. No. 4,409,784 the bale is wrapped with a plastic sheet material immediately upon being formed in a baling machine.
In U.S. patent application Ser. No. 06/752,655, filed July 8, 1985, there is disclosed a tractor operated bale wrapping machine that is movable from bale to bale in a harvested field and adapted to lift the ground supported bale to an upright position on a platform rotatable about a vertical axis. An upright roll of plastic film, carried adjacent the rotatable platform, is wrapped about the bale during its rotation on the platform. The wrapping operation is performed manually so as to require two men for such operation unless the tractor operator, while the tractor engine and power take-off are in operation, dismounts to perform the manual wrapping operation.
The present invention is an improvement over known bale and package wrapping machines and in particular over tractor operated bale wrapping machines by providing for an automatic wrapping of the bale controlled by the tractor operator while seated on the tractor.